APPARATUS, MATERIAL, AND REAGENTS. 31 



Glass Capsules. Small capsules or hollowed- 

 out cubes of crystal glass are employed for cultiva- 

 tions on solid blood serum, on nutrient gelatine, 

 and on agar-agar. They may be procured of 

 white and blackened glass, and are provided with 

 glass slips as covers. 



(K) APPARATUS FOR STORING, AND FOR CULTI- 

 VATIONS IN, LIQUID MEDIA. 



Lister's Flasks. Professor Lister devised a 

 globe-shaped flask with two necks ; a vertical and 

 a lateral one. The lateral one is a bent spout, 

 tapering towards its constricted extremity. When 

 the vessel is restored to the erect position after 

 pouring out some of its contents, a drop of liquid 

 remains behind in the end of the nozzle, and 

 prevents the regurgitation of air through the spout. 

 A cap of cotton wool is tied over the orifice, and 

 the residue in the flask kept for future use. The 

 vertical neck of the flask is plugged with sterilised 

 cotton wool in the ordinary way. 



Sternberg's Bulbs. Professor Sternberg, of 

 America, advocates the use of a glass bulb, provided 

 with a slender neck drawn out to a fine point and 

 hermetically sealed.* 



Aitken's Test-tube. This is an ingenious 

 device for counteracting the danger of entrance of 



* Magnin and Sternberg, Bacteria. 1884. 



